Person:
Antona Peñalba, Beatriz

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First Name
Beatriz
Last Name
Antona Peñalba
URI
https://hdl.handle.net/20.500.14352/79924
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Optometría y Visión
Area
Optica
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2014 - 20152
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    Repeatability of mesopic visual acuity measurements using high- and low-contrast ETDRS letter charts
    (Graefes Archive for Clinical and Experimental Opththalmology, 2015) Barrio De Santos, Ana Rosa; Antona Peñalba, Beatriz; Puell Marín, María Cinta
    To determine the repeatability of mesopic high-contrast (HC) and low-contrast (LC) visual acuity (VA) measurements made at distance and near in healthy young individuals. While the repeatability of photopic VA is well-known, there is a lack of information with regard to the repeatability of VA measured under low luminance conditions. In two different sessions 1 week apart, best-corrected monocular VA was determined using HC (96 %) and LC (10 %) ETDRS charts under mesopic luminance conditions (0.75 cd/m(2)) at distance (HCD, LCD) and near (HCN, LCN) in 47 healthy subjects aged 22.9 +/- 6.8 years. Repeatability was estimated by the Bland and Altman method, whereby the mean difference (MD) and the 95 % limits of agreement were determined as the coefficient of repeatability (COR). Mean logMAR VA values were HCD = 0.09, LCD = 0.44, HCN = 0.21, and LCN = 0.57. Mean differences in measurements between sessions 1 and 2 were not significant, and low in clinical terms (a parts per thousand currency sign1 letter). Repeatability was better for the distance measurements at both high and lowcontrast (COR (HCD) +/- 0.11 and COR (LCD) +/- 0.11 logMAR vs COR (HCN) +/- 0.15 and COR (LCN) +/- 0.16 logMAR), and MDs were also slightly closer to zero for the distance measurements. Similar repeatability was observed between HC and LC VA, both at distance and near. In mesopic conditions, ETDRS charts offer repeatable best-corrected monocular VA measurements. The criterion for a significant change in logMAR VA was 1 line at distance and 1.5 lines at near.
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    Relationship between halo size and forward light scatter
    (British Journal of Ophthalmology, 2014) Puell Marín, María Cinta; Pérez Carrasco, María Jesús; Palomo Álvarez, Catalina; Antona Peñalba, Beatriz; Barrio De Santos, Ana Rosa
    Purpose -To determine the relationship between the size of a halo induced by a glare source and forward scatter or visual acuity (VA) in healthy eyes. Method -Measurements were made in the right eyes of 51 healthy individuals of mean age 29.3±7.5 years. Halo radius was measured using the Vision Monitor and low luminance (1 cd/m2) optotypes presented at a distance of 2.5 m. The visual angle subtended by the radius of the halo was calculated in minutes of arc (arc min). Forward scatter or, straylight, was measured using the compensation comparison technique. Best-corrected distance VA was measured using high contrast (HC) (96%) and low contrast (LC) (10%) Bailey-Lovie logMAR letter charts under photopic (85 cd/m2) and mesopic (0.15 cd/m2) luminance conditions. Results -Mean halo radius was 202±43 arc min (3.4±0.7°) and mean retinal straylight was 0.95±0.12 log units. Mean photopic distance HC-VA and LC-VA were −0.02±0.06 and 0.12±0.09 logMAR, respectively. Mean mesopic distance HC-VA and LC-VA were 0.35±0.11 and 0.74±0.11 logMAR, respectively. Forward stepwise regression analysis revealed that halo radius was significantly correlated with straylight (r=0.45) and mesopic LC-VA (r=0.48), but not with photopic HC-VA and/or LC-VA and mesopic HC-VA. Conclusions -In healthy eyes, the larger the halo size induced by a given glare source, the greater the forwardscatter (straylight) and worse the mesopic LC-VA. Halo size seems to be independent of photopic HC-VA or LC-VA and mesopic HC-VA.